Harman Kardon HK 450 transistor subs

[david winter]

Hi,

I wondered what typical subs should be used in place of those old transistors with roten legs of the same family as the well known 2SC458 (well known for causing problems).

Phono section:
Q701, Q702: 2SC1775(F)
Q703, Q704: 2SA872(E)
Q706, Q707: 2SC1775(F)

Eq sections:
Q501-Q504: 2SC1344(E)
Q505, Q506: 2SA844(E)

Output stages:
Q401-Q406: 2SC1775(F) (*see below)
Q407-Q410: 2SA915(L)
Q411-Q414: 2SC1940(L)
Q417, Q418: 2SD667A(C)
Q419, Q420: 2SC647A(C)
Q421, Q422: 2SD587A(R)
Q423, A424: 2SB617A(R)

(*): old repair made using 2SC1815. Other posts mention KSC1845. However both types don't have the same typical gain.

Misc power etc:
Q1, Q3: 2SA844(E)
Q2: 2SC1419(C)

I didn't find typical voltages on the psu and need to measure once I have received a few parts.
Main psu should be around 35-40 volts, secondary (eq, etc) should be around 12-15V.
Will update this eventually.

Thanks !

 

[Bheriot]

@david winter Did you ever track down replacement transistors?